A large research project in the physical sciences usually involves experimenters, theorists, and people carrying out calculations with computers. There are computers and terminals everywhere. Some of the people hunched over these screens are writing papers, some are analyzing data, and some are working on simulations. These simulations are also quite often on the cutting edge, pushing the world’s fastest supercomputers, with their thousands of networked processors, to the limit. But almost universally, the language in which these simulation codes are written is Fortran, a relic from the 1950s.